North Fremantle shark attack: Evidence-based approaches are key to protecting us from sharks

Heartbreak. I’m feeling it, we’re all feeling it. Stella Berry, a young woman with her life ahead of her, a tragic victim of a suspected fatal shark bite in the Swan River. Everyone is asking questions, including myself, trying to understand how this tragic event unfolded and what can be done to prevent it from happening again. Most jarring, is that this is the first fatality in the Swan River in around 100 years, and the second bite in just as many. Why did this happen? Why now? What can we do about it? The short answer is we don’t know exactly why it happened. Shark bites are random events which, as is the nature of random events, can appear to cluster in time making it seem like there’s both a rhyme and a reason. Statistically, it’s just as likely there won’t be a shark bite for another 50 years in the Swan River but irrespective of ‘when’, one bite is one too many and maths isn’t necessarily going make people feel better about their trip to the river tomorrow, next week or next summer. The incident is being investigated by officials and current information suggests the bite may have been from a bull shark. This species is uniquely adapted to live in rivers, with adults cruising near and in river mouths during warmer periods to breed and give birth. Local reports indicate that tailor and herring are in good numbers at the moment, so it’s possible that the reported dolphins and shark were chasing what appears to be a healthy run of fish. Tragically, it seems a case of wrong place at the wrong time – a terrible accident. The Swan River is popular with boaties and people throwing in a line – I too love to fish (hopeless, I’ll admit) – but there are some tweaks we can make so we can all share the water more safely. These include preferably not fishing for large fish in or near popular bathing areas, and responsibly disposing of animal and food waste. In short, we don’t want to attract sharks to bathing areas, which can in part explain increased sightings and perceived prevalence of sharks. Perth, like Brisbane and Sydney where bull sharks are also common, is situated on one of Australia’s beautiful stretches of coastline, and living next to a big blue wilderness has its inherent risks. Fortunately, the Western Australian Government and local councils are positioned well to improve bather safety in the Swan River given the extensive tagging and tracking program, use of drones, shark barriers, and rebates for shark deterrents. Improved community education and awareness about local environmental conditions and how our own behaviours can reduce risk is a must. For the Swan River specifically, additional measures could include permanently enclosed swimming areas, strategically placed and timed boat patrols with side scanners (the Swan River may not be clear enough for drones to see through), and increased accessibility to effective shark deterrents for the public via the existing rebate scheme. There are pros and cons to each method, but the point is that multiple options are available to improve safety. It’s an emotionally raw time. Feelings of worry, anger and frustration are normal. We’re human. But we need to be thoughtful and utilise evidence-based approaches to reduce risk because anything akin to a cull might make some feel good today, tomorrow or next week, but it won’t achieve the ultimate goal of what we all want - improving people’s safety. Dr Leonardo Guida is a shark scientist with the Australian Marine Conservation Society.